Demon Secrets
by lordlosslove
Summary: Yukio has trouble finding Rin a present for their birthday. He gets help from an unexpected source and it comes with a bit of trouble. (YukioxMephisto) Hinting of BonxRin


**LLL- This is my first Rated M fic. I hope its ok. I love Mephisto…**

Mephisto leans back in his chair, feet propped onto his desk. He can't help but smile in pure merriment. All of his plans have been going perfectly, others better. Nothing could possibly ruin this course of events.

There is a knock at his door. "Come in~~" The large oak mass swings open and in walks Yukio. He has the usual stressed expression on his face and doesn't speak. He simply sits down on the pink sofa, shrouded in thought. Why is he here on such an important human day? "Is there something I can help you with?"

"No."

"Is that so? Then I will assume that my presence simply eases your mind." Yukio glares at him and he shrugs. "You came here." The young teacher says nothing and stares off into space. Mephisto is truly curious now. He has eyes everywhere, knowing clearly what events are occurring but there is something about the twin that has always kept him in the dark. Yukio has never been easy to read. It's like trying to read a book upside down, in a different language, with invisible letters. He gets out of his chair and walks to the distracted teen. Mephisto puts his face so close in front of Yukio's that he can't see anything but him.

Yukio's eyes widen and he sits back into the hideously pink sofa. "I don't know what to get Rin for his birthday."

The demon king raises an eyebrow. "Humans. So simple and trivial."

"Exactly. This is why I know you can't help."

"Just because I am not human doesn't mean I will be of no use in this situation. I am still a gentleman after all."

"What does that have to do with helping me find a gift for Rin?"

"Hush. I'm thinking." Mephisto walks in circles. He swivels around to Yukio. "Got it. Take him on a high ranking mission. Let him fight demons. Take him to a special location where there is a spread of food like no other and then award him with a new sheath for Kurikara."

Yukio stares blankly at Mephisto before smiling. It looks discombobulated since his eyes are still full of confusion. "That's perfect, but where would the mission take him? I don't know of any special places."

"Ghenna."

"No."

"Let the boy go home. Where he belongs."

"If that's the case, why aren't you in Ghenna?"

"It's boring."

Yukio glares at him and shakes his head. "So, where in Assiah can I take him?"

"Wow, I rarely hear you call your home Assiah."

"Shut up or I'm leaving."

"Again, I didn't tell you to come here." Mephisto sits on the arm of the couch next to Yukio."It is your birthday also. He's probably scrambling wondering what to get you."

"I don't want anything."

"Humans are materialistic creatures. You must want something."

"No. I don't."

"I can only imagine how much trouble Rin must be having trying to get you a gift."

Yukio sighs, standing up. "Rin wouldn't bother himself with something like that. I'm off to find somewhere to surprised Rin with."

"Shall I come along?"

"No."

"I won't be a bother." He taps his umbrella onto the floor and poofs into a small dog, leaping into Yukio's arms. A small purple scarf is wrapped around his neck.

Yukio's eyebrows are raised as he holds the dog. "What…!"

"Come now. We must not waste time."

Yukio exits the office. It's beyond even him why he won't just drop the mut to the ground. He walks outside and through the campus of True Cross Academy. A cold breezes blows past his ears, stinging them. It is sunset by this time. The skies are clear, giving off of cool winter glow in the skies. "Maybe I'll take him to an amusement park."

"That is not special. You must do something that will touch his heart."

"Uhm…. the toy store?"

"Do you know anything about your brother."

"I do! I'm just really bad at this."

"It's a great thing I'm here."

"Yukio!" There is a minor scream from a few feet away. They look forward to see two girls running towards them.

He plasters on a smile. "Hello."

Both of the girls are red as apples. The hold out their hands and bow. "Please accept these gifts!"

"Gifts? Wh-what for?" They couldn't have known it was his birthday.

They both partially look up at him. "For Christmas…"

His mind springs into action. "CHRISTMAS! Is that today?"

Both of the girls laugh. "No. Christmas is tomorrow. Today is christmas eve."

Yukio takes the gifts, blushing. Mephisto raises an eyebrow to this expression. "Thank you very much. You two should get inside. You could get sick standing out for too long."

That's when they notice Mephisto and release huge gasps. "Oh! That dog is so cute! Is she yours Yukio!"

"Wha….! No. No. This...this is a friend's dog. I'm watching it."

"She's adorable."

"Oh. Thank you. I'll let my friend know."

They both smile at him and walk away, waving. "Enjoy your gifts!"

"Thank you."

Yukio goes on walking, not speaking. Mephisto has his eyes closed. "I would mind you that I am no female. Actually, male demons have quite extravagant parts..."

"How… did I forget that it was christmas eve? Why didn't you say something?"

"I figured you didn't care. The holiday humans invented to celebrate the birth of Christ. I surely don't care."

Yukio drops the pup to the ground. "And don't get mad at me because you're a purple dog! Of course people would think you're a girl."

Mephisto poofs back into a person/demon. "Well aren't you grumpy. Do girls always approach you that way? They even gave you gifts."

"Yes. Now get focused. I need to think of Rin."

"So considerate. Something I will never understand."

"Well try to!" Mephisto looks at Yukio's face. He really is thinking hard about this. But why? Where is the importance this? Mephisto grabs Yukio's hand, causing him to turn around. "What are you doing?"

"Shut up." Mephisto waves his umbrella. "Ein Zwei Drei." A door appears and Yukio looks around frantically.

"What if someone had seen that!"

Mephisto pulls him along through the door. "You're so much like Shiro and not like him at all at the same time."

When Yukio steps through the door he is met with an unusual sight. There are two large waterfalls flowing into a lake. Grass of the riches shade of green is beneath his feet and over his head is beautiful rock. It is almost as if the entire cave is granite. There are natural lights in the walls and they create a sparkle in the water. Above them is a whole where the moon shines through. Yukio turns to get a full view and sees a fulling grown tree.

His eyes are sparkling with the water. "Where...what is this?"

"This," Mephisto speaks, "is the place where your mother was baptised and your father was sworn in as the Paladin." These words numb Yukio and he walks closer to the water, dropping to his knees. "That is an entire lake of holy water. Be mindful with me around if you don't mind. I try my best to avoid this place."

"Why didn't…." Yukio's words are dry as a lump begins to form in his throat.

"Shiro asked me not to show you or brother this place until one of you became Paladin. He's probably rolling his grave right now but I couldn't resist. You remind me so much of him." Mephisto looks into the air. "This is sacred holy ground. Although I wish to let you stay here as long as you please, I am quickly weakened here and if I'm too weak we won't be able to leave with the infinity key. There of course is another exit, but it's through the Vatican and I am not exactly welcome here."

Yukio stands, still looking at the water. Mephisto is unable to see his face and walks up behind him, carefully. "Why did you bring me here against my father's will?"

"Hmmm, I'm not entirely sure. I'm actually still trying to figure that out myself. You were quite down and stressing over Rin's gift. I figured you need something for yourself. So Merry Christmas…?" The phrase sounds awkward coming from Mephisto's mouth. Yukio still says nothing and the demon king is suddenly uncertain of his choices. "Why not open the gifts you got from those girls…."

Yukio drops the gifts bags leaving Mephisto in even more discontent. Just as the taller demon is about to speak again, Yukio turns around and wraps his arms around Mephisto's neck in a hug. The embrace is tight and unlike anything he has ever felt. It feels like it should be an attack but it's warm and inviting.

Yukio sniffles and Mephisto feels his chest tighten. He tries to look down but Yukio has his face buried in his shoulder. "Thank you." Yukio says, muffled in the fabric of Mephisto's white blazer.

"I…." His words are stuck in his throat as he feels Yukio's body against his own. "It was nothing." Yukio's grip on him tightens and Mephisto's eyes widen when he feels his heart throb. He grabs Yukio's shoulders and shoves him away. "What are you doing?" The teen's eyes are puffy from crying and he is looking at the ground.

"It was a hug. Sorry," Yukio says, wiping his face. "I lost myself."

Mephisto puts his hands on Yukio's face and pulls him so that they are looking in one another's eyes. It's as if he is looking for an answer to his confusion. A sick urge is growing in the pit of Mephisto's stomach the longer he looks into those blue eyes. He doesn't know what to do. Why did he even grab the kid? Why did he bring him here to begin with? That's when Yukio sees something above them. He glances up and Mephisto follows his gaze. It's a green plant with something that looks like white berries.

"A mistletoe?" Yukio whispers, raising an eyebrow.

"What is this plant" Mephisto asks, reaching up to it.

Yukio grabs Mephisto's hand and lowers them from his face, drawing his attention from the holiday plant. "We should go before you get too weak."

He nods in agreement, tapping the ground with his umbrella. "Ein, Zwei, Drei." A door forms and Mephisto opens it, letting Yukio walk through first. The two end up in his office.

Yukio walks to the door, exiting. "Thank you for helping." He doesn't even look back before walking out.

Mephisto feels as if he's done something wrong but he can't put his finger on it. He walks to the door, close to chasing after Yukio but then what? What would he do when he caught up to him. His chest hurts. His stomach hurts. Maybe he swallowed some holy water.

He takes a deep breath, trying to calm himself. The second he closes his eyes he sees Yukio's face. He furrows his eyebrows with a growls. "What is wrong with me?"

Yukio walks through the cold from Mephisto's office. His heart is beating like crazy. What just happened? Why did it happen? The mistletoe appeared. There is a rumor that Mistletoe appears in holy places for those fated to be together. It's the lord speaking and pushing people along but….. why then and there?

Yukio looks up at the clouds where he sees a snowflake. Then two. Then ten. It isn't long before a light snow is coming down over the campus. He grabs his chest through his thick black coat as Mephisto's voice rings through his ears. He's been stressing all day but only then had he felt relaxed. It's actually only with Mephisto that he feels at ease. The man is like a stress repeller.

Yukio finally makes it to his dorm building after a 15 minute walk. It's late and he doesn't want to wake Rin. As he is walking he hears a noise. It sounds like a ghost and Yukio pulls his guns out. He slowly walks down the hall where the sounds get louder. He comes to a room that he hasn't been in yet and peeks his head cautiously through the crack in the door.

That's when his eyes are scarred with a sight he never wanted to see. Rin is in the bed with his face against the mattress and his ass in the air. The noises are coming from him and above him is Bon. With every thrust Bon makes, Rin lets out a different sound. Bon bends down and puts his hand over Rin's mouth, thrusting harder with the other hand on Rin's tail.

Yukio throws his head against the wall and runs down the hall and up to his room. Although he is out of range of the sounds of sweet sex, he can still easily hear sounds of his brother's voice in his ears. He sits in his bed, back against the wall and legs wide open to let his throbbing erection breath. Is it bad that hearing his brother's voice did this to him? No. It can't be. This is normal. Anyone would get hard hearing such a vulnerable….NO!

Yukio removes his coat, school jacket and loosens his tie. He then unbuttons his pants and shoves his hand in his pants to give at least a little relief to the pain. He messages his member through his underwear. He expects his mind to wander off to some cute girl but instead it swerves straight to Mephisto. He wants to snap his eyes open and be disgusted by his actions, but he can't, it feels too good.

He pulls his manhood out of the constricting fabric of his boxers. Precum is leaking out of the tip already. It's been awhile since he's done this. So demons need sexual relief too. Does Mephisto do stuff like this?

The very thought causes him to jolt with ecstasy. This is nothing. He's horny. Anything would turn him on. He increases the stroke of his hand, moving up and down the shaft and rubbing the tip with his finger. "Yes…" His imagination flashes the image of what Mephisto looks like naked. He instinctually begins to move his hips as he gets closer to climaxing.

His voice escapes his mouth again. Just as he is ready to release, there is a puff of smoke and a door appears. Mephisto steps through the door and is halted in his tracks when he sees Yukio laid against a wall, satisfying himself. At that very moment, Yukio cums, thick white liquid streaming from him and across the bed. His body shivers and he is breathing heavily. That release was something he'd been needing for a long time. He slaps his legs shut when he sees Mephisto's wide eyes.

"Why the hell are you barging into other's rooms!"

"I…. uhm." Mephisto eyes travel from the white stain on the sheets to Yukio's legs. Suddenly, he can't help himself. This is what his why he was so sick. This is why the young exorcist was so moody.

Mephisto leaps onto the bed, a devilish grin spread across his face. Yukio tries to push him away. "What are you doing! Get off!"

Mephisto shoves his shoulders down, pinning Yukio onto the mattress. "You were sexually frustrated! How could I not have guessed that."

"I am not…"

"So your hand was good enough for you?" Mephisto snaps his finger and all of his clothes disappear. Yukio's eyes travel down the defined abs that Mephisto has. His tale whips around behind his back and wears nothing but purple boxers. He might as well not be wearing anything. The huge lump pokes through the fabric, begging for release.

"Y-yes.." Yukio's cheeks are red and his hardness is ready to return.

Mephisto tilts his head to the side. The smile shrinks but it doesn't disappear. He bends down and puts his forehead to Yukio's before putting their lips together and connecting them in a kiss. His long tongue finds its way into Yukio's mouth causing the young exorcist to choke in surprise. He tries to pull back but Mephisto grabs the nape of his neck pulling him in deeper.

Mephisto sits up out of the kiss and looks at Yukio's face. He then stands up and snaps his fingers. His clothes appear back on his body. "If you say you are satisfied I will not force you, but try in the future not to tempt me. I shall make my departure." Mephisto walks towards the door.

"Wait." The word escapes his throat and Mephisto turns only so slightly. Yukio won't make eye contact but the need is clear on his face. "Not here… Rin might see."

The smile on Mephisto's face can't get wider. "So somewhere else? My office is vacant."

Yukio still stubbornly won't respond. "Not tonight. I need to gather myself."

Mephisto turns again. "See when the time tempts you." With that, he leaves and the door disappears.

 **LLL- Review if you like. I might only make this a oneshot**


End file.
